From Boston College another failure of climate models to capture reality has been exposed by field empiricism. The map below from NASA’s Earth Observatory will likely have to be revised now that absorption has been demonstrated to be far less.

Up in the air: Heating by black carbon aerosol re-evaluated

First field study finds soot particles absorb significantly less sunlight than predicted by models

CHESTNUT HILL, MA (Aug. 31, 2012) Viewed as a potential target in the global effort to reduce climate change, atmospheric black carbon particles absorb significantly less sunlight than scientists predicted, raising new questions about the impact of black carbon on atmospheric warming, an international team of researchers, including climate chemists from Boston College, report today in the latest edition of the journal Science.

Mathematical models and laboratory experiments used to study airborne soot particles led to projections that the absorption-boosting chemicals that coat black carbon could yield an increase in absorption by as much as a factor of two. But field studies in smoggy California cities found black carbon absorption enhancements of just 6 percent, suggesting that climate models may be overestimating warming by black carbon, the researchers report.

The surprising results highlight the early challenges in a nascent sector of climate science and could have implications for regulatory efforts to reduce the production of black carbon, or soot, by curbing the burning of fossil fuels. Still, scientists agree that black carbon in the atmosphere has a significant effect on global and regional climate, with earlier studies ranking the warming effects of black carbon particles second only to carbon dioxide gas.

“The team’s field measurements in California showed the enhancement of absorption was very small – approximately six percent instead of by a factor of two,” said Boston College Professor of Chemistry Paul Davidovits, an authority on airborne particles, known as aerosols. “In one respect, it shows that nature is much more complicated than our initial laboratory experiments and modeling indicated. Now we will try to unravel and understand that complexity.”

The historic role of black carbon soot in climate change has been well documented by scientists, most notably in the study of ice samples taken from deep within glaciers. For the past several years, Davidovits has collaborated with Aerodyne Research Inc., and colleagues from universities and government labs in the U.S., Canada and Finland. Their research has focused on the chemical and optical properties of sub-micron airborne particles of black carbon produced by commercial and industrial activity.

Unlike carbon dioxide and other greenhouse gasses, which can survive in the atmosphere for decades and centuries, black carbon has a relatively short life span of approximately one to two weeks. Black carbon is part of a group of pollution sources known as Short-Lived Climate Forcers (SLCFs), including methane gas and ozone, which are produced on earth.

During their lifetime, black carbon particles are coated with airborne chemicals, which sophisticated laboratory tests have shown can act like lenses capable of increasing the ability of the particles to absorb sunlight and heat the atmosphere. That has raised a critical question as to whether targeting black carbon emissions in an effort to reduce climate change could yield relatively quick results on a regional or global level.

Led by principal investigators Christopher D. Cappa, a professor of engineering at the University of California, Davis, and Timothy B. Onasch, principal scientist at Aerodyne and an associate research professor of chemistry at Boston College, the team analyzed air samples near the California cities of Los Angeles, San Francisco and Sacramento.

Researchers tested air samples using a combination of real-time techniques, including aerosol mass spectrometry and photoacoustic spectroscopy. These techniques are capable of making measurements to determine the chemical, physical and optical properties of the black carbon particles, said Onasch, whose Billerica, MA-based company has developed the aerosol mass spectrometer instruments.

Onasch said the recent findings set the stage for further studies around the world under different atmospheric conditions in order to better understand how chemical coatings from a range of emission sources affect the absorptive properties of black carbon.

“When you put a soot particle into the atmosphere, we known it contains an elemental carbon component and we know what it’s absorption will be based on mass and size,” said Onasch. “But black carbon particles in the air are constantly changing. They collect inorganic and organic materials, they grow, change shapes, and change composition. These changes affect the absorption or warming capability of the black carbon. So the question remains: to what extent exactly?”

The recent findings only add to the challenge of understanding complex chemical activity in the atmosphere, said Davidovits, whose research is supported by the National Science Foundation’s Atmospheric Chemistry division and the U.S. Department of Energy’s Atmospheric System Research program.

“These findings do require us to reduce our projections about the amount of heating soot produces, at least under some experimental conditions. But the findings don’t point to soot as being a harmless climate forcer,” said Davidovits. “Soot remains an important climate heating agent, as well as a health problem that has been well documented.”

I wonder if the results would be significantly different if the experiments had been conducted in the Arctic rather than in Southern California. The conditions in the two areas would appear to be vary greatly.

In truth, another demonstration of how ASSUMPTIONS for model inputs have been WRONG.
I love the closing shot though, ‘soot remains an important heating agent’..’as well as bad for your health’! Basically saying, ‘OK, it’s not that bad as a forcing agent, but it IS bad for your health!’ FFS, talk about trying to justify continuation of AGW meme by propping on the shoulders of something else!

It’s models all the way down . :-) It’s a rare event that so called scientists get out in the real world . They love their computers and sitting in their comfortable offices surrounded by their fauning admirerers and so we get junk science . Hey , if they got off their duffs and did any work maybe they would figure out new pesticides to deal with all the new problems being imported into the US from foreign countries . I think all so called climate scientists should be defunded and then if they really care about science they can do research on their own dime . You can guess how many of those free ride scumbags would do that . I don’t think they have a real clue as to what the rate of effect of carbon soot is , and no longer am willing to believe them .

“suggesting that climate models may be overestimating warming by black carbon, the researchers report.”

Suggesting??? If I build a house based on a model that it will withstand a Cat 3 hurricane by a factor of 2,and it collapses in a Cat 1,there is no “suggesting” the model is wrong! It is completely fubared. Just more darn weasels words from so called “scientists”. These guys make the inquisitions against Gallileo,Ptomley,Copurnicus,etal look like a game of tag in kindergarten.
And just which GHGs last for centurys? What GHGs where being produced by man 1000 years ago? Inquiring minds want to know. As far as I can see,the only GHG lasting centurys is perhaps all the hot air fraud produced by Mann,Glieck,Black,Jones,NASA,NOOA,UN,etc.

Short lived except (for the effect) on ice? Even on a pro AGW video on Greenland that I watched a few weeks ago, they made a point of showing large areas visually covered with soot that was clearly melted more than the relatively clean areas. They also made a point of showing the accumulation of soot in the bottoms of the meltwater pools, although they did not attribute much to it.

I really wonder if we will one day conclude that man-made soot has been a major driver of Arctic Sea ice melting? I can conceive of at least one method of sheltering an area of Arctic (or Greenland) ice from soot to observe/measure the difference in melting over time.

Don Healy says:
September 3, 2012 at 9:07 am
“I wonder if the results would be significantly different if the experiments had been conducted in the Arctic rather than in Southern California. The conditions in the two areas would appear to be vary greatly.”

There are no coal fired plants blackening the arctic. Soot has to blow in. So, it gets modified in the areas it is produced and passes through.

Will this help to explain why the models have been outpacing reality over the last 10 years? So more retrofitting, fudge factoring and contorted logic will be required to explain the past and keep the fear of CO2 Armageddon rising.

200 percent estimated by computer model= 6 percent actual. This is totally accurate by the standard of climatology.Soon the modellers will be out insisting these measurements show they were right all along and its reality that is in error. “What a bunch of aerosols” indeed.

Still, scientists agree that black carbon in the atmosphere has a significant effect on global and regional climate, with earlier studies ranking the warming effects of black carbon particles second only to carbon dioxide gas.

second only to carbon dioxide gas, which is itself second only to methane, which is second only to something else, ect. ect. ect.

Unlike carbon dioxide and other greenhouse gasses, which can survive in the atmosphere for decades and centuries, black carbon has a relatively short life span of approximately one to two weeks.

The last time I checked, the “life span” of CO2 in the atmosphere is 5 years, so their decades and centuries is based on the idea that the carbon cycle itself can’t grow to absorb the extra, which is deminstraitably false. The biosphere itself is expanding in response to the extra CO2. Meanwhile, their one to two weeks for black carbon is how long it stays in the air. It the drifts down to land on things and continues to convert sunlight to heat energy more efficiently then almost any other substance. For how long? Until it gets washed away by rain, buired under debris, or melts far enough into ice that it no longer absorbs sunlight.

At The Spectator, linked from Bishop Hill, there is a quote that fits climate models, “the enemy of knowledge isn’t ignorance but the illusion of knowledge” attributed to Stephen Hawking at the Paralympic Games opening ceremony. The word “science” could easily be substituted for “knowledge”.

The surprising results highlight the early challenges in a nascent sector of climate science and could have implications for regulatory efforts to reduce the production of black carbon, or soot, by curbing the burning of fossil fuels.
————————————————————
“could have implications for regulatory efforts”

No it won’t. Regulatory tyranny is not based upon reality. Example: diesel emission regulations in California are based upon known fraudulent studies, yet the regulations stand.

All that soot hype comes from 70ties ice age scare. It was man’s fault of course, burning coal. Then warming started, of course it was man’s fault, ’cause he was burning coal.
Aerosol plugin has been an convenient tool how to explain multidecadal, ocean-driven cooling. I have never seen a persuasive study or data that aerosols really matter.

Let’s see, Black carbon in the upper atmosphere intercepts heat that was heading for the ground. Transfers that heat by convection to the upper atmosphere where it is radiated to space. Sounds more like a cooling effect to me. Now if that black carbon falls from the sky onto a surface with a lower albedo (oh I don’t know let’s say ice) the surface it fell on would absorb more heat and accelerate melting. That is more of black carbon’s role. It is a wash in the atmosphere as far as I can see.

During their lifetime, black carbon particles are coated with airborne chemicals, which sophisticated laboratory tests have shown can act like lenses capable of increasing the ability of the particles to absorb sunlight and heat the atmosphere.

So they grow and become better sunlight absorbers, yielding more heat.

Unlike carbon dioxide and other greenhouse gasses, which can survive in the atmosphere for decades and centuries, black carbon has a relatively short life span of approximately one to two weeks. Black carbon is part of a group of pollution sources known as Short-Lived Climate Forcers (SLCFs), including methane gas and ozone, which are produced on earth.

Then when these grown-larger particles leave the atmosphere and are deposited on surfaces, suddenly they no longer contribute heat to the nearby atmosphere?

Must be similar to the well-understood principle where a rock, heated by the sun, never heats up the air around it, it only heats the ground it rests on. Then the ground, in turn, will specifically retain the heat gained from the rock and prevent it from heating the atmosphere while only allowing other heat to warm the air above it.

Well, at least it must be well-understood by whoever programmed the models that are saying that’s true for black carbon particles.

Ah, yes. The insidius Dihydrogen Monoxide. Nasty stuff, that. Kills millions every year. I’ve been patitioning the government to ban it for years. Did you know it can even corrode steel? And while it’s not as strong a GHG as Carbon Dioxide on a molicule per molicule bases, it can easily get up to even higher concintrations in the atmosphere. Best to outlaw it completely.

Owen in Ga says:
September 3, 2012 at 1:58 pm
Let’s see, Black carbon in the upper atmosphere intercepts heat that was heading for the ground. Transfers that heat by convection to the upper atmosphere where it is radiated to space. Sounds more like a cooling effect to me.

Correct. Atmospheric black carbon warms the troposphere, which means it cools the surface, and cools the climate as the residence time of that energy in the climate system is reduced.

Led by principal investigators Christopher D. Cappa, a professor of engineering at the University of California, Davis, and Timothy B. Onasch, principal scientist at Aerodyne and an associate research professor of chemistry at Boston College

People with no particular expertise in the field, climbing onboard the AGW gravy train.

Short lived except (for the effect) on ice? Even on a pro AGW video on Greenland that I watched a few weeks ago, they made a point of showing large areas visually covered with soot that was clearly melted more than the relatively clean areas.

The Abstract says:

…atmospheric black carbon particles absorb significantly less sunlight than scientists predicted, raising new questions about the impact of black carbon on atmospheric warming….

Soot on ice, in ice, or at the bottom of a glacial pond is not atomospheric soot.

LazyTeenager says:
September 3, 2012 at 4:21 pm
So if soot is not so important it must mean the CO2 is more important. That’s gotta hurt.
>>>>>>>>>>>>>>>>>

When I read the article, I thought to myself, how long before someone tries to gleefully spin this as meaning that CO2 has a larger role in warming than previously thought? Up steps Lazy to the plate, attempting to rub our nose in it.

I’m not even going to bother explaining why you cannot draw that conclusion from this stidy Lazy. I just want to know one thing.

What kind of a sick puppy are you that you announce with glee that you think you have evidence that CO2 os worse than previously thought? What makes you hate yourself and humanity so much that you wish the worst upon us?

So if soot is not so important it must mean the CO2 is more important. That’s gotta hurt.

Water vapor is the most important GHG of all, far more important that CO₂. Alarmists cannot even make the transition from AGW to Catastrophic AGW without the assistance of water vapor acting as a positive feedback (when the evidence shows there’s actually a negative feedback).

So CO₂ was only a bit player at around current atmospheric concentrations, will remain a bit player at the predicted future concentrations, of only negligible importance compared to water vapor.

So how much more important could CO₂ have been made, when it was negligible compared to water vapor to begin with?

davidmhoffer says:
September 3, 2012 at 6:15 pm
LazyTeenager says:
September 3, 2012 at 4:21 pm
So if soot is not so important it must mean the CO2 is more important. That’s gotta hurt.
>>>>>>>>>>>>>>>>>

What kind of a sick puppy are you that you announce with glee that you think you have evidence that CO2 os worse than previously thought? What makes you hate yourself and humanity so much that you wish the worst upon us?
++++++++++++++++++++++++++

It’s not complex. He’s just another loser who has time on his hands to to work for the cause. That being to make everyone else a loser so he can fit in. Good luck with that LT.

So these sooty particles absorb incoming sunlight, which therefore does not reach the ocean and get stored deep in the ocean. The hot rocks then fall into the ocean along with their hitch hiking heat, and sink to the bottom along with their solar energy captives.

Seems like a net plus to me; the solar energy still gets to the ocean, and the air gets cleaner and better for your health, unless you eat a lot of soot eating fish.

Schitzree says: “…And while it’s not as strong a GHG as Carbon Dioxide on a molicule per molicule bases, [dihydrogen monoxide] can easily get up to even higher concintrations in the atmosphere. Best to outlaw it completely.”

I think we can can allocate exa-dollars to be spent preventing evaporation of that bastardly evil GHG, Dihydrogen Monoxide. We can cook up a plan to roof over the Oceans. Imagine the megabucks that we can abscond with a project to do that. It would be hardly noticeable amongst the quintillions of bucks allocated to do the job.

It must be remembered that temperature declined from about the 1940s to the 1970s, a period when CO2 was increasing rapidly. To explain this, models have assumed a cooling impact from man-made aerosols. Emissions of aerosols increased during this period and then decreased during the 1970’s and beyond with environmental regulations. Models assumed that aerosols cooled the surface of the earth from the 40’s to the 70’s, after which their impact was reduced and global warming from CO2 resumed. If the impact of aerosol emissions is significantly reduced, then the models will need another mechanism to explain the cooling from the 40’s to the 70’s. If not, this cooling period presents a problem for CO2 global warming theory in that this period of cooling occurred during a period of increasing man-made CO2 emissions.